The present invention relates to novel DC-88A derivatives. The compounds have an excellent antitumor activity and are useful as antitumor agents.
WO 87/06265 (EP-A-0271581) discloses DC-88A produced by microorganisms belonging to the genus Streptomyces exhibits not only an antibacterial activity against various bacteria but also an antitumor against lymphocytic leukemia P388, etc.
DC-88A has the following structure. ##STR4##
DC-89A1 which is a compound having a structure similar to DC-88A is disclosed in WO 87/06265; DC-89A2, DC-89B1 and DC-89B2 are disclosed in Japanese Patent Application No. 182866/88. DC-89A1, DC-89A2, DC-89B1 and DC-89B2 have the following structures. ##STR5##
These compounds show an antibacterial activity against various bacteria and an antitumor activity against lymphocytic leukemia P388, etc.
CC-1065 and its derivatives which are structurally similar to DC-88A and exhibit an antitumor activity are also disclosed in Japanese Published Unexamined Patent Application Nos. 64695/79 and 193989/85.
DC-88A derivatives having an excellent antitumor activity have always been demanded.